// Copyright 2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "internal/platform/implementation/linux/ble_l2cap_socket.h"

#include <sys/poll.h>
#include <sys/socket.h>
#include <unistd.h>

#include <algorithm>
#include <cstdint>
#include <cstring>
#include <optional>
#include <string>
#include <utility>

#include "absl/strings/string_view.h"
#include "absl/time/time.h"
#include "internal/platform/implementation/crypto.h"
#include "internal/platform/logging.h"
#include "proto/mediums/ble_frames.pb.h"

namespace nearby {
namespace linux {

BleL2capInputStream::~BleL2capInputStream() { Close(); }

ExceptionOr<ByteArray> BleL2capInputStream::Read(std::int64_t size) {
  std::vector<char> buffer(size);

  pollfd pfds[1];
  pfds[0].fd = fd_raw_->get();
  pfds[0].events = POLLIN;
  ssize_t rcvd = 0;

  while (rcvd < size) {
    int r = poll(pfds, 1, -1);
    if (r < 0) {
      if (errno == EINTR) {
        continue;
      }
      return Exception{Exception::kIo};
    }
    if (pfds[0].revents & POLLIN) {
      auto r = recv(fd_raw_->get(), buffer.data() + rcvd, size - rcvd, 0);
      if (r < 0){ return Exception{Exception::kIo};}
      rcvd += r;
    }
  }


  return ExceptionOr{ByteArray(std::string(buffer.begin(), buffer.end()))};
}

Exception BleL2capInputStream::Close() {
  if (!fd_raw_->isValid()) return {Exception::kSuccess};
  fd_raw_ -> reset();
    return {Exception::kSuccess};

}
BleL2capOutputStream::~BleL2capOutputStream() { Close(); }

Exception BleL2capOutputStream::Write(absl::string_view data) {
  pollfd pfds[1];
  pfds[0].fd = fd_raw_->get();
  pfds[0].events = POLLOUT;
  ssize_t sent = 0;

  while (sent < data.size()) {
    int r = poll(pfds, 1, -1);
    if (r < 0) {
      if (errno == EINTR) {
        continue;
      }
      return Exception{Exception::kIo};
    }
    if (pfds[0].revents & POLLOUT) {
      auto r = send(fd_raw_->get(), data.data() + sent, data.size(), 0);
      if (r < 0){ return Exception{Exception::kIo};}
      sent += r;
    }
  }
  return {Exception::kSuccess};
}

Exception BleL2capOutputStream::Close() {
  if (!fd_raw_->isValid()) return {Exception::kSuccess};
  fd_raw_ -> reset();
    return {Exception::kSuccess};
}

BleL2capSocket::BleL2capSocket(int fd,
                               api::ble::BlePeripheral::UniqueId peripheral_id,
                               std::string service_id
                               )
    : fd_(std::make_shared<sdbus::UnixFd>(fd)), input_stream_(std::make_unique<BleL2capInputStream>(fd_)),
      output_stream_(std::make_unique<BleL2capOutputStream>(fd_)),
      peripheral_id_(peripheral_id)
      {}

BleL2capSocket::~BleL2capSocket() { Close(); }



Exception BleL2capSocket::Close() {
  if (!fd_->isValid()) return {Exception::kIo};
  fd_ -> reset();
    return {Exception::kSuccess};
}


void BleL2capSocket::SetCloseNotifier(absl::AnyInvocable<void()> notifier) {
}

bool BleL2capSocket::IsClosed() const {
  return closed_;
}

}  // namespace linux
}  // namespace nearby